Expansion joints are used mainly to absorb dimensional changes caused by thermal movements of a pipeline. They consist of bellows formed from a thin-walled stainless steel tube.
Bellows expansion joints are preferred to other methods of absorbing pipe movements such as pipe loops and slip-type joints. Pipe loops are wasteful of space while slip joints require regular maintenance. Additionally, loops and slip joints are capable of absorbing movement that is in line with the pipe only. Bellows joints require no maintenance and allow many types of movement in a compact space.
Bellows expansion joints are available in flanged, weld, grooved or threaded ends. Internal liners to prevent erosion of the inner surface of the bellows and the induced vibrations by the flowing fluid are available.
Optional features include tie rods to restrain pressure thrust and shrouds to protect the outer surface of the bellows from damage in buried installation. Consult Kinetics for proper anchoring and guiding of pipe with expansion joints to prevent extending or buckling of joints due to pressure thrusts.